1. Field of Invention
The present invention relates to a remote coordinate input device and input method used when either designating a specified portion on a screen, or operating application software when performing a presentation by projecting an enlarged display of a computer screen onto a screen using a projector.
2. Description of Related Art
In a conventional presentation, information is displayed on a large screen by projecting an enlarged display of a transparent-type document using an OHP (overhead projector), or by projecting an enlarged film image using a slide projector. A demonstrator conducts the presentation while designating important points of the projected image using a pointing stick or a laser pointer.
Moreover, in recent years, due to the wide distribution of personal computers and liquid crystal projectors, effective presentations have been performed using various application software that have been developed for presentations.
However, a mouse or similar device which is connected to the computer must be operated in order to display the screen. In order to operate the mouse or similar device, the demonstrator must move away from being in front of the screen. Unfortunately, this movement by the demonstrator and the movement of the pointer on the screen are not related to each other. Thus, the audience is sometimes distracted.
In order to avoid this problem, devices which do not restrict the position of the demonstrator when the demonstrator is operating the computer, and which allow the operator to operate the application software by directly operating on the screen from a comparatively free position, and which can input so-called remote coordinates are being developed, and various corresponding methods have also been developed.
As one example of these methods, Japanese Patent Laid-Open Publication No. Hei 5-19953 discloses a method of controlling displayed information by operating a remote control device from a position which is distant from the screen. However, the operation is only performed by various kinds of keys that are provided on the remote control device. For example, in order to move the pointer on the screen, arrow keys have to be pressed. However, in this method, the pointer only moves integratedly, which provides a different feel than one gets from pointing by using a pointing stick.
Moreover, Japanese Patent Laid-Open Publication No. Hei 2-300816 discloses a method in which three light emitting elements are provided on a designating part. Each light emitting element radiates light in a different direction. The angle of orientation of the designating part is detected by the difference in strength of the light received by the light receiving elements from the light radiated from the light emitting elements. However, since the light has to be modulated in order to distinguish the light emitting elements, the apparatus is subject to problems, such as the designating part becoming complicated and it being easily influenced by external noise because the device uses the light amount difference.
Moreover, both of these methods have difficulty in distinguishing between two points or more that are simultaneously designated by the demonstrator and another person, such as someone in the audience.